A secret U.S.-funded biological weapon to wipe out the heroin trade is in the final stages of development, raising fears in the scientific community that a monster germ will wreak an “ecological catastrophe.”

For the past two years, scientists funded by the U.S. and British governments have been developing a killer fungus that they say destroys the opium poppies that produce the raw material for heroin.

Their base of operations is a lab in a high-security former Soviet biological weapons lab in Uzbekistan called the Uzbekistan Genetics Institute.

Now, scientists at the rundown plant are using their lethal expertise not only to isolate the fungus known as Pleospora Papaverecea, but also to figure how to genetically engineer it to make it more aggressive, according to United Nations officials supervising the project.

They’ve also developed a formula in which the fungus spores would be mixed with a talc and silica gel to make it a liquid weapon that could be sprayed from aircraft over poppy fields in central Asia.

The idea, says Edward Rosenquist, director of International Operations for the U.S. Department of Agriculture, is to create a safe, cheap and efficient “silver bullet” to eradicate drug crops rather than use harmful and expensive chemical herbicides.

Lab testing of the new weapon has recently been completed and the Uzbeki group’s research soon will be submitted to the larger scientific community for “peer review,” said Sandro Tucci, director of the U.N.’s Drug Control Program, which is supervising the project.

Tucci told The Post that in field trials the genetically manipulated fungus caused opium poppies to wilt and die but left 130 other species unharmed.

But the possible introduction of the genetically altered organism into the environment has created a firestorm.

“This is biological warfare. It runs the risk of causing an ecological catastrophe. It is a hideously bad idea,” said Ed Hammonds of the Sunshine Project, an Austin, Texas-based public interest group.

Many scientists warn that the culture could mutate and attack other plants – and possibly animals and humans.

“There are all kinds of ways that the DNA of the organism could spread, mutate and create hybrids, and I think there needs to be a great deal of care put into this before it is even considered,” said Dr. Sheldon Krimsky, professor of Urban and Environmental Policy at Tufts.

There are also fears that, once sprayed in Afghanistan, for example, terrorist groups could easily gain access to the fungus and use it to create their own organisms for revenge attacks on other crops.

Tucci calls such fears unfounded.

“The idea that this is some kind of plot from ‘Dr. No’ that a monster is being created in a laboratory is nonsense. The United Nations does not engage in these kinds of things,” he said.

The Clinton administration last year won congressional approval to spend $23 million to research “bio-active” materials for the war on drugs.